416 THE SPINAL CORD. 



lumbar regions, is soon followed by catarrhal inflammation of the 

 urinary passages. This gives rise to an abundant production of 

 altered mucus, which in its turn, by causing an alkaline fermenta- 

 tion of the urine contained in the bladder, converts it into an irri- 

 tating and ammoniacal liquid, which reacts upon the mucous mem- 

 brane and aggravates the previous inflammation. 



We find, therefore, that the spinal cord, in its character of a 

 nervous centre, exerts a general protective action over the whole 

 body. It presides over the involuntary movements of the limbs 

 and trunk ; it regulates the action of the sphincters, the rectum, 

 and the bladder ; while at the same time it exerts an indirect influ- 

 ence on the nutritive changes in those parts which it supplies with 

 nerves. 



